For the power pulse transmitters that have to deliver a reduced power of n dB by application of a discrete control signal, the use of the following methods is known:                adding at the output of a transmitter, a power switch enabling or not enabling an n dB attenuator,        adding between two low power stages, a switch enabling or not enabling either an n dB attenuator or an n dB amplifier stage,        varying the DC power supply of n class C bipolar stages.        
However, these devices present certain drawbacks:
The power switch notably introduces losses. The power amplifier must therefore be more powerful than is necessary for its operation. Thus, it must always operate at a maximum power. Furthermore, the layout has to allow the attenuator to be integrated.
The difficulty is to guarantee an identical gain of the following stages for each of the two power levels. This problem soon becomes insurmountable when it concerns a wideband amplifier.
The power variation range is limited to 2 dB per class C bipolar stage.
The invention relates to a device for controlling at least two peak power levels for an amplifier operating in pulse mode, characterized in that it comprises at least the following elements:
a premodulation stage comprising at least:
                a first amplifier stage, comprising at least one amplifier and a processing device suitable for supplying a squarewave signal to the amplifier,        a second amplifier stage, comprising at least one amplifier and a processing device suitable for supplying a signal having a shape roughly identical to the shape of the applied modulation,A power-locked stage comprising at least:        a coupler and detector for sampling at least a part of the signal at the output of the amplification subsystem and sending it to a video amplifier,        a peak detector and a level discriminator suitable for generating a modulation signal to an amplifier,        power supply means for the amplifiers.        
The device and the method according to the invention offer notably the following advantages:                the system makes it possible to ensure the integrity of the transmitted Gaussian pulse, accurately regulate its peak power levels throughout the frequency band concerned and obtain performance levels that are stable temperature-wise,        reduced dimensions, weight and volume for the onboard applications,        the system is fast enough to ensure sufficient agility of the power variation and the widest possible variation range without sacrificing accuracy.        
Still other objects and advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein the preferred embodiments of the invention are shown and described, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious aspects, all without departing from the invention. Accordingly, the drawings and description thereof are to be regarded as illustrative in nature, and not as restrictive.
The device and the method according to the invention rely notably on the gain control of n stages of an amplification subsystem rather than on the use of devices allowing for an attenuation which is synonymous with pointless losses.
The invention consists notably, through a detection of the transmitted signal on the one hand and the use of a variable-gain RF amplifier on the other hand, in generating a Gaussian-form pulse signal of amplitude controlled by a digitized locking system having two or more peak power levels that can be selected by a discrete signal.